Thanks for your reply!
I have had performance issues on this machine before, so no shadow over Decker. What surprised me is that it handled the web version better than the native build, which intuitively felt backwards, but the (for me unnoticed) drop in fps might be the explanation for that.
I'll definitely try to build Decker with graphics acceleration enabled and see if that makes any difference on my device. I might also experiment with changing the frame rate and see if that makes it calm down.
Thanks again!